Conventional washing machines typically include a basket that holds articles such as clothes to be washed, an agitator disposed within the basket which agitates the clothes in the basket, and a motor which drives the agitator and the basket. The motor is typically a permanent magnet synchronous motor, which can reverse its rotation direction to achieve different modes in the wash cycle.
The motor assembly can include a rotor and a stator. The stator must be positioned such that an air gap is present between the rotor and stator. However, it is very important that the air gap between the rotor and stator be minimized to improve the efficiency of the motor. Air gap is a measure of the distance between rotor magnets on the innermost diameter of the rotor and the outermost diameter of poles of the stator. As such, the more accurately that the rotor and stator can be located, the smaller the air gap that will be present. Decreasing the air gap that is present can also allow for the use of less material and weaker magnets in the stator, thus resulting in a lower cost motor.
Thus, a need exists for a motor assembly that allows for a decreased air gap.